# NOTE:
# Alternative to use this helper is to inherit from ActiveRecord::Generators::Base
# which provides the #next_migration_number class method that lets #migration_template work as expected
# 
module RailsAssist::Migration    
  class << self   
    attr_accessor :rails_root_dir
    attr_accessor :orm
  end

  def self.included(base) #:nodoc: 
    base.extend ClassMethods  
  end

  def next_migration_number(dirname) #:nodoc:
    orm = RailsAssist::Migration.orm || Rails.configuration.generators.options[:rails][:orm]
    require "rails/generators/#{orm}"
    "#{orm.to_s.camelize}::Generators::Base".constantize.next_migration_number(dirname)
  rescue
    raise NotImplementedError
  end

  module ClassMethods    

    def migration_lookup_at(dirname) #:nodoc:
      Dir.glob("#{dirname}/[0-9]*_*.rb")
    end

    def migration_exists?(dirname, file_name) #:nodoc:
      migration_lookup_at(dirname).grep(/\d+_#{file_name}.rb$/).first
    end 
    alias_method :first_migration_file, :migration_exists?              

    def latest_migration_file(dirname, file_name) #:nodoc:
      migration_lookup_at(dirname).grep(/\d+_#{file_name}.rb$/).sort.last
    end 

    def current_migration_number(dirname) #:nodoc:
      migration_lookup_at(dirname).collect do |file|
        File.basename(file).split("_").first.to_i
      end.max.to_i
    end

    def next_migration_number(dirname) #:nodoc:
      orm = RailsAssist::Migration.orm || Rails.configuration.generators.options[:rails][:orm]
      require "rails/generators/#{orm}"
      "#{orm.to_s.camelize}::Generators::Base".constantize.next_migration_number(dirname)
    rescue
      raise NotImplementedError
    end
  end
end